I am currently facing issues with importing/saving my custom parameters file. Loading the parameters from file, then refreshing and writing the parameters seems to be no issue. After I rebooted my Pixhawk, I compared the parameters in Mission Planner, but certain parameters do not update, even when I attempt to refresh or synchronize them or load the same file again. I also tried resetting the parameters to default before loading the parameters from file, but that does not seem to make any difference. I added a screenshot of the parameters that won’t change.
It is normal, some of them have a different value due floating point number representation (like 36.364 vs 36.3639984) and some of them are initialised during bootup, like Gyro offsets and calibration or STAT_ variables.
I now understand that many of the differences are due to floating point rounding errors or involve read-only parameters.
As for COMPASS_DEV_ID and COMPASS_DEV_ID2, I should mention that these are read-only parameters, which may explain why I’m seeing issues with them not updating. However, when I compare them after uploading several times the same custom parameter file, they always seem to have the same value. Is this behavior normal, or should I be concerned if these values don’t change after an upload? My understanding is that since they identify the compass hardware, these values should remain consistent unless there’s a hardware change?
Yes that is correct, you changed the order of the compasses, by declaring one of them external and/or disabling one or more of them.
That caused the order to change, Or do you have a CAN compass?
I’m not using a CAN compass, just the standard compasses connected through I2C.
On both drones, the COMPASS_DEV_ID values are the same, as I’m using the same compass hardware on both.
However, there is a difference in the configuration:
On the first drone, the external box is not checked for the primary compass.
On the second drone, the external box is checked for the primary compass, and the orientation is different.
It seems that the compass order has changed due to these differences in the external setting and orientation. I haven’t disabled any compasses, but it seems like the primary compass on one drone is marked as external, while on the other it’s treated as internal.
Is it expected behavior for the COMPASS_DEV_ID to remain the same, even though one is marked external and the other isn’t? Should I adjust the external setting on the first drone as well?
(I tried importing the params file from drone one to the second one, to have the same settings just for declaration)
That is not the best way of doing things, the best way is to use ArduPilot Methodic configurator to configure one vehicle, then copy the vehicle configuration directory and re-do the configuration for the second one using the copyed files.
That is a lot safer and both vehicles will be functional in the end. And it saves time.
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